In the current gas-cooled fuel cell systems, the cooling field and the reacting field on the two sides of the cathode flow field plate are not connected. The cooling gas and the reacting gas are supplied by different gas-supply systems. The cooling gas is normally supplied using an independent fan. Generally, the gas pressure is within a few hundred Pa (measured with barometer; same as described below). For the reacting gas, depending on the operating pressure, a fan or a gas-pump is used to supply the reacting gas, and the pressure ranges from a few hundred Pa to a few atoms. Depending on the environment, different gas-supply system can be used. The system controls the respective rate of flow of the reacting gas and the cooling gas, and the pressure of the reacting gas is also adjustable, thereby accurately controlling the level of humidity of the membrane electrode assembly in a fuel cell. Thus the fuel cell operates under a desirable humidity condition and maintains desirable electricity generation performance. However, there are disadvantages associated with a cathode flow field plate with separated cooling and reacting gases. For example, the control systems are relatively complicated, and the gases are relatively difficult to control. The complexity of a control system for a small fuel cell group generating a few hundred-watts is comparable to that of a large fuel cell group generating over ten kilowatts. Therefore, the cost for small fuel cell groups generating below a kilowatt remains high thus hindering the process of commercialization.